Canadian psychologists pored over 60 published studies and articles, half of which examined the effects of medical marijuana, while the other half looked at recreational use. Because cannabis research is so young, pulling data from both types of studies provides the best confirmation yet that pot really can enhance — or even save — lives.

The researchers took up this review in order to give doctors solid evidence to inform their conversations with patients. “There is so little guidance in this area, which inspired us to do this work,” says lead study author Zach Walsh, a psychology professor at the University of British Columbia. “I get so many calls from colleagues asking what to tell patients who use cannabis to help deal with an alcohol dependency or depression or a bad back.”

Of course, anecdotal evidence has long pointed to pot’s mental-health benefits. “In general, people who use cannabis say it helps them relax and reduces anxiety,” Walsh says. “And we know that many PTSD sufferers are using cannabis to treat their symptoms.” Now with more hard science backing its use for both anxiety and PTSD, he hopes doctors will talk more openly and realistically about marijuana with their patients. Just like any drug, it won’t work for everyone and can have side effects, but Walsh firmly believes it should be part of the conversation.

The evidence for clinical depression wasn’t quite as strong as for PTSD and anxiety, but it was solid enough to suggest marijuana may help. “Depression is often co-occurring with chronic pain or other health issues,” Walsh says. “Many say medical cannabis improves mood while also addressing primary symptoms.”

Multiple large studies showed that marijuana may be a godsend for people plagued by an opiate addiction. “It’s the substitution effect,” Walsh says. “When you replace a harmful drug with a less harmful drug, it’s a big benefit from a public health standpoint. In some states where medical marijuana is legal, there has been a 25 percent reduction in opioid overdoses.” Research also suggests weed may help alcoholics ween off booze.

Obviously, much of America faces one big roadblock to reaching for cannabis: the law. But as prohibition quickly crumbles away, more people are gaining access to marijuana and more doctors — and even some addiction professionals — are becoming comfortable with the drug. It’s also opening the door for research, which should further solidify cannabis’s medicinal value.

“I believe cannabis should be treated the same as other medicines,” says Walsh. “It should be held to the same standards and subject to the same risk-versus-benefit evaluations. We know that its negative effects are certainly tolerable compared to those of many medications we use, so let’s not leave behind all the people who aren’t finding relief in traditional therapies.